The Effect of Pressure and of Controlled Stretch on the Luminescent Properties of 9,10-Bis(phenylethynyl) Anthracene

Quick Fabrication of Large-area Organic Semiconductor Single Crystal Arrays with a Rapid Annealing Self-Solution-Shearing Method

In this paper, we developed a new method to produce large-area single crystal arrays by using the organic semiconductor 9, 10-bis (phenylethynyl) anthracene (BPEA). This method involves an easy operation, is efficient, meets the demands of being low-cost and is independent of the substrate for large-area arrays fabrication. Based on these single crystal arrays, the organic field effect transistors exhibit the superior performance with the average mobility extracting from the saturation region of 0.2 cm² V⁻¹s⁻¹ (the highest 0.47 cm² V⁻¹s⁻¹) and on/off ratio exceeding 10⁵. In addition, our single crystal arrays also show a very high photoswitch performance with an on/off current ratio up to 4.1 × 10⁵, which is one of the highest values reported for organic materials. It is believed that this method provides a new way to fabricate single crystal arrays and has the potential for application to large area organic electronics.

Positioning and joining of organic single-crystalline wires

Organic single-crystal, one-dimensional materials can effectively carry charges and/or excitons due to their highly ordered molecule packing, minimized defects and eliminated grain boundaries. Controlling the alignment/position of organic single-crystal one-dimensional architectures would allow on-demand photon/electron transport, which is a prerequisite in waveguides and other optoelectronic applications. Here we report a guided physical vapour transport technique to control the growth, alignment and positioning of organic single-crystal wires with the guidance of pillar-structured substrates. Submicrometre-wide, hundreds of micrometres long, highly aligned, organic single-crystal wire arrays are generated. Furthermore, these organic single-crystal wires can be joined within controlled angles by varying the pillar geometries. Owing to the controllable growth of organic single-crystal one-dimensional architectures, we can present proof-of-principle demonstrations utilizing joined wires to allow optical waveguide through small radii of curvature (internal angles of ~90–120°). Our methodology may open a route to control the growth of organic single-crystal one-dimensional materials with potential applications in optoelectronics.

Aligned, one-dimensional, single-crystal materials may allow on-demand photon/electron transfer. Here, the authors use a physical vapour transport technique to grow organic single-crystal wires with the guidance of pillar-structured substrates, and perform proof of concept waveguide experiments.